1. Field of the Invention
The invention relates to an objective lens drive, and more particularly, to a mechanism for adjusting the tilt of an optical axis of an objective lens.
2. Description of the Related Art
An apparatus for adjusting the inclination (tilt) of an optical axis of an objective lens with respect to a disk in an optical pickup has already been known.
In an optical pickup, one end of a suspension is fixed to a portion of a base, and a lens holder is fixed to the other end of the suspension, thus supporting the lens holder in a cantilever fashion. A magnet or a coil is provided on the lens holder, and the objective lens is driven in focusing and tracking directions by means of electromagnetic interaction developing between the lens holder and a magnetic circuit disposed on the base side of the optical pickup. In order to adjust the optical axis of the objective lens, there has already been known a configuration in which there is provided a piezoelectric element whose one end is fastened to a lower section of the base and whose other end is fixed to a portion for supporting the suspension and in which the piezoelectric element is actuated so as to act as an arm, thereby inclining the lens holder. Please refer to the following publication for further information.
Japanese Patent Laid-Open Publication No. Hei 9-50637.
However, the related-art technique has a configuration in which a piezoelectric element is provided in a lower section of the base as an arm or drive means, to thereby adjust the tilt of the optical axis of the objective lens. Provision of the piezoelectric element raises a problem of an increase in the thickness of the optical pickup. Particularly, in recent years, a demand exists for a more slim objective lens drive as represented by a CD drive, a DVD drive, or a combination drive doubling as a CD drive and a DVD drive, which is to be incorporated into a notebook personal computer. A mechanism involving an increase in thickness is not preferable.